/* bmp280_example.ino Example sketch for BMP280 Copyright (c) 2016 seeed technology inc. Website : www.seeedstudio.com Author : Lambor, CHN Create Time: Change Log : 2021/03/11 by @Kongduino Reworked example to display true altitude based on MSL The MIT License (MIT) Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #undef max #undef min #include #include "Seeed_BMP280.h" #include #include // http://librarymanager/All#ArduinoJSON BMP280 bmp280; #define INTERVAL 2000 double t0; uint32_t MSL = 102009; // Mean Sea Level in Pa void setup() { Serial.begin(115200); delay(2000); Serial.println("\n\nBMP280 test"); if (!bmp280.init()) { Serial.println("Device not connected or broken!"); } } void loop() { double t1 = millis(); if (t1 - t0 > INTERVAL) { float p1; //get and print temperatures Serial.print("Temp: "); float t = bmp280.getTemperature(); Serial.print(t); Serial.println("C"); //get and print atmospheric pressure data Serial.print("MSL: "); Serial.print(MSL / 100.0); Serial.println(" HPa"); Serial.print("Pressure: "); p1 = bmp280.getPressure(); Serial.print(p1 / 100.0); Serial.println(" HPa"); //get and print altitude data float a = bmp280.calcAltitude(MSL, p1, t); Serial.print("Altitude: "); Serial.print(a); Serial.println(" m"); Serial.println("\n"); t0 = millis(); } if (Serial.available()) { char mb[255]; uint8_t ix = 0; while (Serial.available()) { mb[ix++] = Serial.read(); } mb[ix] = 0; Serial.println("Incoming:"); Serial.println(mb); JsonDocument doc; DeserializationError error = deserializeJson(doc, mb); if (!error) { float newMSL = doc["MSL"]; Serial.print("New MSL: "); Serial.println(newMSL); if (newMSL > 0.0) { MSL = newMSL * 100; } } else { Serial.println("Parse error!"); } } }